Nanoscale Carbon Materials for Contaminant Separation - Nanotechnologies for Water Environment Applications - page 269

CHAPTER 10
Nanoscale Carbon Materials for Contaminant
Separation
Tung Xuan Bui and Heechul Choi
10.1 Introduction
Among the numerous forms of carbon, nanoscale carbon materials, with size in
the range of 1-100 nm, have captured a great deal of attention from scientists. These
carbonaceous materials are diverse in terms of structure and morphology as well as their
physical, chemical, and mechanical properties. For example, spherically shaped carbon
nanostructures are composed of carbon black, fullerenes, carbon nanoparticles, carbon
onions, and nanoporous carbon (Rao and Dresselhaus, 2001). Rod shaped nanocarbon
structures can be constructed from various types of carbon nanotubes such as filled
carbon nanotubes, carbon nanotube junctions, and Y-junction carbon nanotubes. Carbon
nano-parallenepipeds, carbon rings, graphitic nanocones, and carbon nanohorns are also
important members of the nanoscale carbon family (Rao and Dresselhaus, 2001). In this
chapter, selected materials that can be applied in the environmental field for contaminant
separation will be further discussed, including carbon nanotubes, fullerenes, carbon
nanoparticles, carbon nanofibers, and nanoporous carbon (mesoporous carbon).
10.1.1 Fullerenes
Fullerenes were discovered in 1985 through a study of the carbon clusters
obtained from the vaporization of a graphite disk by laser irradiation under a helium jet
(Kroto et al., 1985). Fullerenes are a caged carbon with an even number of carbon atoms
(ranging from C 20 to a few hundred) (Ajayan, 1999; Lu and Chen, 2005); the most
investigated and stable fullerenes are C 60 and C 70 . As a consequence of the Euler's
principle, one fullerene can be constituted of many hexagons [C 2n has (n-10) hexagons]
but exactly 12 pentagons (Figure 10.1).
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